ABSTRACT
Toxicologic studies of nonnutritive or low caloric sweetening agents have on several occasions demonstrated tumorigenic effects for the mammalian lower urinary tract, that is, renal pelvis, ureter, urinary bladder, and urethra. The urinary bladder as a target tissue for carcinogenic effects of cyclamates and saccharin was first demonstrated through use of the mouse intravesical pellet implantation technique. Mice were individually anesthesized with pentobarbital and diethyl ether. Each study mouse had a pellet surgically placed into the urinary bladder lumen by the technique of Jull as modified by Allen et al. The method used for the introduction of aqueous solutions into the mouse bladder has been published. Briefly, after anesthetization, a low abdominal midline incision was made, the bladder and urethra were exposed, and the urethra was carefully dissected away from the dorsal-lying vagina. The ligatures were successively tightened to prevent leakage of the solution as the needle was removed.
